Solderless wire connector

ABSTRACT

A wire connector contact having a pair of spaced, multi-slotted, interconnected, contact elements, the portion interconnecting the contact elements being relieved at both ends to produce greater flexibility in the outside legs of the contact elements.

Unite States Patent 1191 Bazil1e,.,1r.

11] 3,869,190 1451 Mar. 4,1975

[ SOLDERLESS WIRE CONNECTOR [75] Inventor: 'James H. Baz ille, Jr North Saint Paul, Minn.

[73] Assignee: Minnesota Mining and Manufacturing Company, Saint Paul, Minn.

[22] Filed: Mar. 29, 1974 [21] Ap'pl. No.: 456,135

[52] US. Cl. 339/98 [51] Int. Cl H0lr 11/20 [58] Field of Search 241/97 R, 97 P, 98, 99 R;

[56] References Cited UNITED STATES PATENTS 3.605.072 9/1971 Driscoll 339/98 3,683,319 8/1972 Vigeant ct aim. 339/97 R 3,793,611 2/1974 Johansson 3,793,612 2/1974 Driscoll 3,812,449 5/1974 Elm .11. 339/98 Primary Examiner-Joseph H. McGlynn Assistant Eraminer-Howard N. Goldberg Attorney, Agent, 01' Firm-Alexander, Sell,.Ste1dt & DeLaHunt [57] ABSTRACT A wire connector contact having a pair of spaced, multi-slotted, interconnected, contact elements, the portion interconnecting the contact elements being relieved at both ends to produce greater flexibility in the outside legs of the contact elements.

6 Claims, 7 Drawing Figures PATENTED 4|975 '3 869 190 sum 1 or 2 1 j SOLDERLESS WIRE CONNECTOR FIELD OF THE INVENTION BACKGROUND OF THE INVENTION Solderless wire connectors utilizing multi-slotted flat plate contact members like that of the present invention have previously been described, for example, in

Levin et al US. Pat. No. 3,012,219 and in Elm US. Pat. Nos. 3,258,733 and 3,388,370. These connectors provide excellent electrical contact with insulated wires of appropriate diameter, but require surprisingly high application forces, particularly for larger wire sizes or for simultaneous connection to a number of wires. The required force has been reduced previously by internally perforating at least the interior legs of the contact elements to provide stress relief along the wire contacting edges thereof as described in Driscoll US. Pat. No. 3,605,072. I

Persons applying solderless. wire connectors in the field have generally been found to use a pair of line mans pliers. The force that an average person can exert with such a pliers has, therefore, been regarded as a limitation on the force requirement for making a connection with a solderless wire connector. Thus far this requirement has limited solderless wire connector contacts for use on the No. 14 AWG and No. 12 AWG wires most common in home wiring to two wire slots. However, in'branch circuit wiring of residential, commercial and industrial buildings it is frequently desired to connect three wires. To make such a connection two two-wire contacts have been used in a single insulating connector body.

SUMMARY OF THE- INVENTION spaced planar interconnected resilient contact ele-.

ments having multiple wire receiving slots defined by parallel extended legs," each slotin one element being aligned with a slot in the other element. The portion interconnecting the contact elements is relieved at both ends, each relief extending inward from the end to alignment with the outer edge of the first wire receiving slot. The flexibility in the outside legs of the contact elements is increased by the reliefs and the application force requirement is thereby substantially reduced. A three wire connector constructed-in accordance with the present invention can be applied to No. 14 AWG or No. 12 AWG wire using a linemans pliers under normal hand pressure.

DESCRIPTION OF rue DRAWING In the drawing:

FIG. I is a side elevation view of a wire connector contact constructed in accordance with the present invention in an insulating connector body;

FIG. 2 is a top plan view thereof;

FIG. 3 is a cross-sectional view taken along line 3-3 of FIG. 2;

FIG. 4 is a perspective view of the connector contact;

FIG. 5 is a bottom view of the contact;

FIG. 6 is an end vi ew of thecontact; and

FIG. 7 is a plan view of the contact into the U-shape.

The connector 10 includes an insulating body 11 and a doubly folded-spring compression reserve wire connector contact 12.

The wire connector contact I2 comprises a pair of spaced, planar, interconnected, resilient contact elements 14 and 15 having wire receiving slots 17, 18 and 19 defined by parallel extended legs 21, 22, 23 and 24. Each slot 17, l8, 19 in one element 14, 15 is aligned with a corresponding slot 17, 18, 19, respectively, in the other element. The portion 27 interconnecting the contact elements 14 and 15 is relieved at both ends in smooth arcs 29 and 30. The end portions of the contact elements 14 and 15 adjacent the interconnecting portion 27 are formed with smoothly arcuate-curves 32 and 33 reverse that of the adjacent relief 29 and 30, respectively. The reverse curves 32 and 33 are blended into the curvature of the corresponding relief to form a smooth continuous curve to prevent-any stress concentration point.

The reliefs 29 and 30 and the curving of the outside legs 21 and 24 at 32 and 33 serve to make the outside legs more uniform in width through the curved portions thereof and therefore more flexible. This substantially reduces the force required to press prior to folding the contact 12 into the insulating body 11 and onto wires therein. The force requiredis further reduced by internally perforating at 35 the internal legs 22 and 2 3 of each contact element 14 and 15 to provide stress relief along the wire contacting edges thereof.

The insulating body 11 has side walls 37, end walls 38 and inner walls .39 defining three parallel open-faced wire receiving channels 41, 42 and 43. Transverse grooves 45 and 46 in the side and inner walls 37 and 39 permit insertion of the doubly folded contact 12, shown partially inserted in FIGS. 1 and 2. The contact'slots 17, 18 and 19 align with the axisof the appropriate wire receiving channel so as to make full spring compression reserve contact with the wire supported in the channel I when the contact is forced thereagainst. A cover 48 is in collars '50 and 51 and end walls 38 have a diameter provided, to be folded and locked in place over the exposed upper surfaces of the contact elements after the contacts have-been completed.

Channels 41 and 42 are open only at one end, i.e.,

. through circular openings in collar 50 and the adjacent end wall 38. Channel 43, on the other hand, is open at both ends, i.e., at collars 50 and 51. As a result, wire ends inserted through the sleeve 50 into the channels 41 and 42 will each be stopped within the body 11 in position for making electrical connection with the contact 12 and a wire inserted into channel 43 in a three-wire pigtail splice, a tap splice or an in-line splice.

In a specific example of a connector 10 for use with No. 14 to No. 12 building wire, the body is made of polypropylene and the circular wire accepting openings of 0.180 inch. The contact 12 has an overall length of 0.630 inch. The slots 17, 18, 19 are each 0.046 inch wide and the centerline to centerliine spacing between adjacent slots is 0.190 inch. The relietcurves 29 and 30 are on a 0.062 inch radius, the furthest inward extent thereof aligning with the outer edge of the first slot at the respective ends. The reverse curves 32 and 33 in the outside legs 21 and 24 are on a 0.125 inch radius, the center being on the center line of the nearest slot 0.206 inch along the center line from the end of the .I 3 legs; The slo'tsare each 0.230 inch deep being smoothly radiused at their innermost ends. The internal perforations 35 in legs 22 and 23 are generally centered in the respective legs and are 0.031 inch wide and 0.175 inch long, being smoothly radiused at the ends thereof.

In'tests, the connector justdescribed was compared against a similar connector wherein the contact did not have the reliefs 29 and Comparisons were made between the force required to apply the contacts to 12 gauge solid copper wire having TW plastic insulation. It was found that the application force required for the unmodified three-wire connector was 488 pounds while that constructed in accordance with the present invention only required 382 pounds force. This is the difference which prevents the unmodified threewire contact from being applied using a linemans pliers while the three-wire contact 12 of the present invention may be applied in that manner.

The reduction in application force attained with the contact of the present invention was found in further tests to be achieved without degradation of the electrical connection which must be made. In fact, it was found that when the contacts were removed from the wires the outside legs of the contact of the present invention returned more closelyto theiroriginal position thereby indicating that they would better follow cold flow of the wire than would theunmodified contact.

I claim: I

l. A spring compression reserve wire-connector contact, comprising a pair of spaced planar interconnected resilient contact elements having multiple wirereceiving slots defined by parallel extended legs, each slot in one element being aligned with a slot in the other element, and the portion interconnecting the contact elements being relieved at both ends, each relief extending inward from the end to alignment with the outer edge of the first wire receiving slot.

2. The wire-connector contact of claim 1 wherein each contact element is formedwith four legs defining three wire receiving slots.

3. The wire-connector contact of claim 2 wherein the two internal legs of each contact element are internally perforated to provide stress relief along the wirecontacting edges thereof.

4. The wire-connector contact of claim 3 wherein each wire receiving slot is 0.046 inch wide.

5. The wire-connector contact'of claim 1 wherein the .portion interconnecting the-contact elements is rewire-contacting edges thereof. 

1. A spring compression reserve wire-connector contact, comprising a pair of spaced planar interconnected resilient contact elements having multiple wire-receiving slots defined by parallel extended legs, each slot in one element being aligned with a slot in the other element, and the portion interconnecting the contact elements being relieved at both ends, each relief extending inward from the end to alignment with the outer edge of the first wire receiving slot.
 2. The wire-connector contact of claim 1 wherein each contact element is formed with four legs defining three wire receiving slots.
 3. The wire-connector contact of claim 2 wherein the two internal legs of each contact element are internally perforated to provide stress relief along the wire-contacting edges thereof.
 4. The wire-connector contact of claim 3 wherein each wire receiving slot is 0.046 inch wide.
 5. The wire-connector contact of claim 1 wherein the portion interconnecting the contact elements is relieved at both ends in smooth arcs and wherein the end portions of the contact elements adjacent the interconnecting portion are formed with smoothly arcuate curves reverse that of the adjacent relief, which reverse curves are blended into the curvature of the relief.
 6. The wire-connector contact of claim 1 wherein each leg internal of the two end legs of each contact element is perforated to provide stress relief along the wire-contacting edges thereof. 